Subintimal Angioplasty (SIA) versus Bypass for Critical Lower Limb Ischaemia (CLI) in Patients with TASC C and D Lesions. 5-year Result.

OBJECTIVES:
High patency and Limb-salvage rates are possible in units specialised in open and endovascular management of CLI.
Primary aim is to compare effectiveness of SIA with standard bypass surgery (BS) in maintaining amputation free survival. Secondary endpoints are risk of Major Adverse Events (MAE), Quality Time without Symptoms of disease or Toxicity of Treatment (Q-TWiST) and cost-effectiveness.

METHODS:
Form 2001-2007, 1276 patients were referred with PVD. We prospectively compared 334 primary procedures (SIA=206, BS=128) in 309 patients (N_SIA=190, N_BS=119) with CLI. Mean age (SIA 73+/-13yrs vs. BS 70+/-14yrs, p=0.127) and co-morbidity severity scores (P>0.05) were similar between groups. 55% were females in the SIA group vs. 35% in OS, p=0.0005.

RESULTS:
5-year all-cause survival was similar for SIA 78.6% [95%CI 72.2%-8.9%] and BS 80.1% [95%CI 72.0%-86.5%], p=0.7343, h=1.10 [95%CI=0.65-1.87]. 5-year amputation-free survival was also similar (SIA 72.9% [95%CI 66.2%-78.7%] vs. BS 71.2% [95%CI 62.5%-78.7%], p=0.9765, HR=0.95 [95%CI=0.60 to 1.51]).
5year-Primary patency was similar between groups, SIA 72.8% [95%CI=66.1%-78.6%] vs. BS 65.3% [95%CI=56.3%-73.3%], p=0.7001, h=1.10 [95%CI= 0.69 to 1.74]. 5-year assisted primary patency was improved but not significantly with SIA, 82.8% [95%CI=76.8%-87.6%] vs. 68.2% [95%CI=59.3%-76.0%], p=0.1061, h=0.65 [95%CI 0.38 to 1.11]. 5-year secondary patency rates were also improved with SIA, 85.9% [95%CI=80.3%-90.2%] vs. 72.1% [95%CI=63.4%-79.5%], p=0.2624, h=0.71, [95%CI =0.39 to 1.30].

5-year risk of re-intervention was similar between groups (p>0.05) and mean number of procedures (+/- SD) were SIA 1.19+/-0.50 vs. BS is 1.10+/- 0.41, p=0.078.

Risk of MAE (P<0.002) and length of hospital stay (LOS_SIA14+/-16days vs. LOS_BS24+/-23days, P<0.0001) were significantly reduced with SIA. Q-TWiST was significantly improved (P<0.001) and cost per QALY (P<0.05) reduced with SIA.

CONCLUSIONS:
In high volume specialised centres SIA and BS give similar technical outcomes. However SIA provides significant cost-effective improvements in patient-specific Q-TWiST. SIA enhances symptom-free survival, is minimally invasive and allows for high patient turnover without compromising limb salvage. Intermediate-term patency is higher than commonly reported because of routine duplex follow and aggressive intervention in symptomatic patients.